what is the use of css opacity?

Opacity describes a substance's transparency, with 1 being completely opaque, 0.5 being somewhat see-through, and 0 being totally transparent. Notably, when an element's background is made translucent using the opacity attribute, all of its child elements likewise turn transparent.

• Opacity specifies how transparent something is, with 1 being fully opaque, 0.5 being partially see-through, and 0 being completely transparent. Note: All of an element's child elements also become transparent when the opacity property is used to make an element's background translucent.